PALO ALTO, Calif. — Driving around a college campus can be treacherous. Bikes and scooters zip out of nowhere, distracted students wander into traffic, and stopped cars and speed bumps suddenly appear. It takes a vigilant driver to avoid catastrophe.

Jesse Levinson does not much worry about this when he drives his prototype Volkswagen Touareg around the Stanford University campus here. A computer vision system he helped design keeps an unblinking eye out for pedestrians and cyclists, and automatically slows and stops the car when they enter his path.

Someday soon, few drivers will have to worry about car crashes and collisions, whether on congested roads or on empty highways, technology companies and car manufacturers are betting. But even now, drivers are benefiting from a suite of safety systems, and many more are in development to transform driving from a manual task to something more akin to that of a conductor overseeing an orchestra.

An array of optical and radar sensors now monitor the surroundings of a growing number of cars traveling the nation’s highways, and in some cases even track the driver’s physical state. Pedestrian detection systems, like the one that Mr. Levinson, a research scientist at Stanford’s Center for Automotive Research, has helped design, are already available in luxury cars and are being built into some midrange models.

The systems offer auditory, visual and mechanical warnings if a collision is imminent — and increasingly, if needed, take evasive actions automatically. By the middle of this decade, under certain conditions, they will take over the task of driving completely at both high and low speeds.

But the new systems are poised to refashion the nature of driving fundamentally long before completely autonomous vehicles arrive.

“This is really a bridge,” said Ragunathan Rajkumar, a computer science professor who is leading a Carnegie Mellon University automated driving research project partly financed by General Motors. “The driver is still in control. But if the driver is not doing the right thing, the technology takes over.”

Although drivers — at least for now — remain responsible for their vehicles, a host of related legal and insurance issues have already arisen, and researchers are opening a new line of study about how humans interact with the automatic systems.

What the changes will mean to the century-old American romance with the car remains to be seen. But the safety systems, the result of rapid advances in computer algorithms and the drastically falling cost of sensors, are a practical reaction to the modern reality of drivers who would rather talk on the phone and send text messages than concentrate on the road ahead and drive.

Four manufacturers — Volvo, BMW, Audi and Mercedes — have announced that as soon as this year they will begin offering models that will come with sensors and software to allow the car to drive itself in heavy traffic at speeds up to 37 miles per hour. The systems, known as Traffic Jam Assist, will follow the car ahead and automatically slow down and speed up as needed, handling both braking and steering.

At faster speeds, Cadillac’s Super Cruise system is intended to automate freeway driving by keeping the car within a lane and adjusting speed to other traffic. The company has not said when it will add the system to its cars.

Already actions like steering, braking and accelerating are increasingly handled by computer software rather than the driver.

“People don’t realize that when you step on antilock brakes it’s simply a suggestion for the car to stop,” said Clifford Nass, a director at the Center for Automotive Research at Stanford. How and when the car stops is left to the system.

The automobile industry has been motivated to innovate by growing evidence that existing technologies like the antilocking braking systems and electronic stability control have saved tens of thousands of lives.

In November, the National Transportation Safety Board recommended that all new cars be equipped with collision avoidance technologies, including adaptive cruise control and automatic braking. Two states — California and Nevada — have passed laws making it legal to operate self-driving cars as long as a human being is inside, able to take over.

The National Highway Traffic Safety Administration recently reported that one system, electronic stability control, or E.S.C., which digitally detects the loss of traction and compensates automatically, saved 2,202 lives from 2008 to 2010. Federal safety regulations began phasing in electronic stability control on small trucks and passenger vehicles in 2007.

“I think E.S.C. is an amazing piece of technology,” said David L. Strickland, the National Highway Traffic Safety administrator. “And I do think there are a number of new technologies that the agency is looking at right now that have tremendous promise.”

Innovation and deployment of the crash-resistance technologies accelerated after 2010, with news that Google had a secret program to design self-driving cars. Google has not said whether it intends to sell its vehicles. However, the search engine company has actively lobbied for laws in several states legalizing autonomous automobiles.

Ten automakers have advanced research laboratories based in Silicon Valley. The most recent one was established by Ford Motors in Mountain View, Calif., in June.

Also playing a role in the speed with which safety changes are being made are component suppliers like Bosch and Mobileye, an Israeli company that specializes in cameras mounted to look forward from the car’s rearview mirror, and elsewhere on advanced vehicles.

Adaptive cruise control, known as A.C.C., and self driving are now aided by costly radar-based systems, but that will change with the next generation of low-cost video camera technology, said Amnon Shashua, co-founder, chairman and chief technology officer of Mobileye.

“No radar is needed,” said Dr. Shashua, who is also a professor of computer science at Hebrew University. “This could bring A.C.C. to the masses.”

An emerging communications technology that will give vehicles a much more elaborate and instantaneous view of their surroundings is being tested in Ann Arbor, Mich.; Europe and elsewhere. Called “connected vehicle technology” by Dr. Rajkumar — and nicknamed V2X by the auto industry — it allows a vehicle to detect cars around corners that a human driver would be unable to see.

“V2X offers tremendous opportunities to make for a more efficient and safer driving experience,” said Paul Mascarenas, chief technical officer at Ford Motor’s Research Division.

The actions of drivers, too, are being rethought. When drivers are no longer required to maintain a constant vigil on the road ahead at all times, it will still be necessary to reclaim their attention in emergencies. Dr. Nass is establishing an automotive industry consortium to develop new computerized systems that make it safer to switch back and forth from human to computer control.

Dr. Rajkumar said he suspected that most Americans were not quite ready for a fully autonomous car.

But, he said, “In time, as society becomes more comfortable and legal concerns are ironed out, full autonomy will become practical, inevitable and necessary.”

He, for one, would welcome an automated car for his 30-minute commute home. If the car could drive itself, he said, he would happily take a short nap.

I hope so, but only because the amount of stupid shit I see on the road. Nothing gets me more pissed off than watching idiots drive. Grandpa doing 45 in the fast lane, morons who can't keep their A.D.D in check long enough to get through a 4 way stop sign in a timely fashion, idiots that stop at a light 5 car lengths behind the person in front of them, selfish assholes that while in the left lane cut across all lanes to make the right 20 feet ahead of them, rather than just going to the next street and turning around, **** tards that make a right into the drive way that you're coming out of without using a signal so you have to wait there while this idiot is oblivious to what's going on. I could go on and on and on.

I hope so, but only because the amount of stupid shit I see on the road. Nothing gets me more pissed off than watching idiots drive. Grandpa doing 45 in the fast lane, morons who can't keep their A.D.D in check long enough to get through a 4 way stop sign in a timely fashion, idiots that stop at a light 5 car lengths behind the person in front of them, selfish assholes that while in the left lane cut across all lanes to make the right 20 feet ahead of them, rather than just going to the next street and turning around, **** tards that make a right into the drive way that you're coming out of without using a signal so you have to wait there while this idiot is oblivious to what's going on. I could go on and on and on.